The present invention relates to novel functionalized electrophiles, their analogous initiators, and processes for preparing these compounds. The present invention also relates to homotelechelic, heterotelechelic, and radial functional polydiene polymers, polyarylene polymers and polydiene/polyarylene copolymers, their optionally hydrogenated analogues, their optionally deprotected analogues, and processes for preparing these functionalized polymers.
Terminal functionalization of living polymer anions with various electrophiles has been extensively studied. See, for example, U.S. Pat. Nos. 3,786,116 and 4,409,357. More recently, Hirao and Nakahamna have introduced the concept of functionalization with an electrophile that contains a protected functional group. This group can then be removed from the polymer (xe2x80x9cdeprotectionxe2x80x9d) in a subsequent step. For examples of protected electrophiles in the synthesis of functionalized polymers, see K. Ueda, A. Hirao, and S. Nakahama, Macromolecules, 23, 939 (1990) and M. Tokyamo, A. Hirao, S. Nakahama and K. Takenaka, Macromol. Chem. Phys., 197, 3135 (1996).
Recently, protected acetal and carboxylic acid electrophiles were disclosed, see M. P. Labeau, H. Cramail, and A. Deffieux, Polymer International, 41, 453 (1996) and A. Hirao, H. Nakahama, T. Ishizone, and S. Nakahama, Macromolecules, 26, 2145 (1993), respectively. The articles report polymerizing styrene using butyl lithium to form the living polymer anion. Using the protected acetal and carboxylic acid electrophiles, the resulting polymers included a protected functionality at one end of the polymer chain.
The present invention provides novel compounds useful as electrophiles for incorporating a protected functionality into a living polymer anion. In particular the electrophiles incorporate a protected carbonyl or carboxyl group into a living polymer. The electrophiles are represented by the formula: 
wherein:
each X is independently halogen, preferably selected from the group consisting of chloride, bromide and iodide;
each Z is independently a branched or straight chain hydrocarbon connecting group which contains 1-25 carbon atoms, optionally substituted with aryl or substituted aryl;
each T is independently selected from the group consisting of oxygen, sulfur, nitrogen, and mixtures thereof;
(Axe2x80x94R1R2R3) is a protecting group, in which each A is independently an element selected from Group IVa of the Periodic Table of the Elements; and R1, R2, and R3 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, and substituted cycloalkyl;
R, R4, and R5 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl and substituted cycloalkyl;
h is 0 when T is oxygen or sulfur, and 1 when T is nitrogen;
l is an integer from 1 to 7;
m is 1 when T is oxygen or sulfur, and 2 when T is nitrogen;
n is 2 or 3; and
w is 0 or 1,
with the proviso that each T in structure (I) cannot equal oxygen.
The invention also provides hydrocarbon compositions including at least one protected functionalized initiator, which can also be useful for incorporating a protected carbonyl or carboxyl functionality into a polymer structure, as well as processes for making the initiators of the invention. The initiators are represented by the following structures: 
wherein:
each M is independently an alkali metal, preferably selected from the group consisting of lithium, sodium, and potassium;
each Z is independently a branched or straight chain hydrocarbon connecting group which contains 3-25 carbon atoms, optionally substituted with aryl or substituted aryl;
each Q is independently a saturated or unsaturated hydrocarbyl group derived by incorporation of one or more compounds selected from the group consisting of conjugated diene hydrocarbons, alkenylsubstituted aromatic compounds, and mixtures thereof into the Mxe2x80x94Z linkage;
each v independently ranges from 0 to 5;
each T is independently selected from the group consisting of oxygen, sulfur, nitrogen, and mixtures thereof;
(Axe2x80x94R1R2R3) is a protecting group, in which each A is independently an element selected from Group IVa of the Periodic Table of the Elements; and R1, R2, and R3 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl aryl, substituted aryl, cycloalkyl, and substituted cycloalkyl;
R, R4, and R5 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, and substituted cycloalkyl;
h is 0 when T is oxygen or sulfur, and 1 when T is nitrogen;
l is an integer from 1 to 7;
m is 1 when T is oxygen or sulfur, and 2 when T is nitrogen;
n is 2 or 3; and
w is 0 or 1.
Compounds (III) and (IV) efficiently polymerize conjugated diene hydrocarbons, alkenylsubstituted aromatic compounds, and mixtures thereof to afford living polymer anions. The resultant polymer anions, functionalized with a protected functional group at the head, can be quenched to afford a mono-functional polymer; reacted with functionalizing agents to form homo- or hetero-telechelic polymers; or coupled to form telechelic or functionalized radial polymers.
The present invention also provides polymers produced using the electrophiles and/or initiators above, as well as process for making such polymers. In this embodiment of the invention, each T of structure (I) may be oxygen.
Such polymers are useful materials in their own right. For example, polymers derived from electrophiles (I) or (II) and/or initiators (III) or (IV), in which T is N, can be useful in the production of tires with low hysteresis. In addition, the polymers derived from electrophiles (I) or (II) and/or initiators (III) or (IV) can be optionally deprotected, either before or after optional hydrogenation, to afford polymers with carboxyl, aldehyde or ketone end groups. These end groups can enter into subsequent copolymerization reactions to form copolymers. Alternatively, the deprotection and copolymerization can be conducted in the same step to afford the copolymer directly.